The 2011 Great East Japan Earthquake

Sendai Plain
Field Guidebook

Cover photograph: View of the Sendai Plain from Sendai Airport, looking seaward (taken March 2013).

The 2011 Great East Japan Earthquake

Sendai Plain Field Guidebook

Field guidebook working group: International Research Institute of Disaster Science, Tohoku University
Published Japanese version (1st March 2014), translated in English (6th August 2014)

The 2011 Great East Japan
Earthquake

Sendai Plain
Field Guidebook

東北大学災害国際研究所

1. Preface
A Mw 9.0 earthquake on March 11, 2011, triggered alarge-scale tsunami that struck the Pacific coast of easternJapan. The tsunami inflicted widespread and severe damage
to coastal areas of the Tohoku district. The disaster ensuingfrom the 2011 earthquake and tsunami, one of the severest
disasters in Japanese history, is called “The Great East Japan
Earthquake” (hazard name is “the 2011 off the Pacific Coastof Tohoku Earthquake” defined by the Japan Meteorological
Agency). The recovery process in tsunami devastated areas
is ongoing. Many scientific data have been collected sincethe 2011 event. Many issues remain to be resolved, such as
mental and financial care for the victims, reconstruction ofdevastated residential areas, and long-term monitoring.
Since the 2011 disaster, many people have visited the Figure 1: Stops in this field guidebook.
tsunami-devastated area to understand what happened on
March 11, 2011 and to ascertain how the recovery work has been progressing. We believe thatpersistent visits by people from other areas to the tsunami-devastated areas might encourage
the people in those areas who were strongly affected by the disaster. It is expected to be worthwhile for people living in those areas and for those who must confront future tsunami risks.
In this context, we have noticed that there is no appropriate guidebook for the 2011 disasterin terms of its academic aspects. It is apparently difficult for people who want to know where
to look. The International Research Institute of Disaster Science (IRIDeS), Tohoku University,
was founded in April 2012 to develop action-oriented scientific studies for natural disasters.
The faculties of IRIDeS have been conducting field trips to the tsunami-devastated areas continually. This guidebook was edited based on leaflets and reports that were prepared and used
for earlier field trips. We selected nine sites of tsunami-related locations from the Sendai Plain.
A person might be able to visit these sites by car within a single day (Fig. 1). Moreover, thisguidebook explains earlier and ongoing plans for disaster prevention in this area, and presents
descriptions of historic and prehistoric records of past large-scale tsunamis.
We hope this guidebook will be useful for you to understand the characteristics of large-scale
earthquakes and tsunamis better, and to act for future natural disasters. We note especially that
this guidebook was first published in Japanese on March 2014 and was then translated into
English on August 2014. Situations in tsunami-devastated areas have been changing continuously day by day. We expect that some of the guides might not fit what might be observed in
the field at the time of your visit. In addition, most sites introduced in this guidebook are within
residential areas or near them. We sincerely appreciate that you might take appropriate care ofthat fact when in the field.
Chapters 2, 4, 5, and 7 of this guidebook were reprinted (or modified) from a guidebook
published for field excursions of the 2013 annual meeting of the Geological Society of Japan.
March 2014 (translated in English on August 2014)
Yuichi Ono, Yoshi Abe, Suppasri Anawat, Mas Erick, Miwa Kuri, Kazuhisa Goto, Daisuke
Sugawara

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The 2011 Great East Japan
Earthquake

Sendai Plain
Field Guidebook

Stops
Stop 1 Nakahama Elementary School, Yamamoto Town (37°54'60.0"N 140°55'03.6"E)
Stop 2 Hill of Millennium Hope, Iwanuma City (38°07'35.8"N 140°56'02.7"E)
Stop 3 Sendai Airport (38°08'15.3"N 140°55'47.0"E)
Stop 4 Yuriage, Natori City (38°10'20.4"N 140°57'14.3"E)
Stop 5 Idoura, Sendai City (38°11'02.0"N 140°57'33.6"E)
Stop 6 Arahama, Sendai City (38°13'06.7"N 140°59'05.5"E)
Stop 7 Teizan Canal (38°13'10.6"N 140°58'57.5"E)
Stop 8 Sendai Tobu Highway (38°13'53.1"N 140°57'14.4"E)
Stop 9 Sueno Matsuyama, Tagajo City (38°17'15.6"N 141°00'12.1"E)

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The 2011 Great East Japan
Earthquake

Sendai Plain
Field Guidebook

東北大学災害国際研究所

2. Geological setting of Sendai Plain
Sendai Plain has been developed fromsediments supplied from rivers (Abukuma,
Natori, and Nanakita rivers) and coastal sanddrifts. The plain is characterized by topographic features such as beach ridges (sanddunes), natural levees, and back marshes. The
plain elevation is 10 m at most. The coastal
area within a few kilometers from the present
coastline has particularly lower elevations(0–3 m; Fig. 2). A 40-km-long, continuous
sandy beach has developed on the Sendai Bay
coast, stretching from Gamou, Sendai City at
the northernmost area to Isohama, Yamamoto
Town at its southernmost extent. The sanddune has a typical elevation of 3–4 m andcomprises medium-grained sand (0.25–0.50mm). Since the early Edo period (ca. 400 yearsago), many Japanese black and red pine trees
have been planted on the coastal sand dunes
to protect farmlands that had been developedin the marshlands. The sand dune nearest to
the present coastline had been regarded as
higher than natural conditions because of thetrapping of wind-blown sands by the coastal
forests (Ito, 2006). Engineered coastal dikes
Figure 2: Bathymetry and topography of the Sendai Bay area. The tsunami
had been built on top of the sand dune. The
inundation area is based on Haraguchi and Iwamatsu (2011) (modified after
Sugawara and Minoura, 2013).
dikes installed before the 2011 tsunami had
been designed as countermeasures against
storm surges. The elevation of the topmost part of the dike was 5–6 m. The implementationof the coastal dikes remained ongoing at the time of the 2011 Tohoku earthquake. Vertical or
oblique walls were employed for the dikes, depending on the location and year of construction.
In the present Sendai Plain, three to four rows of the beach ridges are identified. In general,they are the traces of the coastal sand dunes in the past time. Small coastal lakes are found in
the marshlands located between the older beach ridges (Matsumoto, 1981). The paleo-coastlineof the Sendai Plain about 6,000 years ago (Jomon period) was situated 5–8 km inland of thepresent shoreline because of the sea-level rise during the warm period after the Last Glaciation.
Since then, the sea level dropped continually, causing a gradual seaward migration of the shoreline, and formation of the sandy beach ridges. In Sendai City, three beach ridges (I, II, and III,
which are located respectively 3, 2, and 1 km from the present shoreline) can be recognized. The
formation ages of the beach ridges were dated at 5,000–4,500 yrBP for the ridge I, 2,800–1,600
yrBP and 1,000–700 yrBP for the ridges II and III, respectively (Matsumoto, 1984). The beachridge III is divisible into three sub ridges (IIIa, IIIb, and IIIc). The formation ages of the sub
ridges IIIa, IIIb and IIIc were estimated at ca. 1,300 yrBP, 1,100 yrBP, and 350 yrBP, respectively

5The 2011 Great East Japan
Earthquake

Sendai Plain
Field Guidebook(Ito, 2006). The area of the Sendai Plain had been expanding during the last 5,000 years. The
rate of shoreline migration is calculated as 0.4–1.1 m/yr (Matsumoto, 1994).
Natural levees are found near the rivers and old (buried) channels. The levees comprise
medium-grained sands, which were deposited by major floods. Lowlands near the levees arecovered by fine sediments such as silt and clay. Human activities in the past are evident inmany archeological sites found from the older beach ridges and natural levees. Extensive
development of rice paddies and dry fields in the Sendai Plain started after the establishmentof the old Sendai Castle by the feudal lord, Masamune Date, about 400 years ago. Until thattime, land use of the plain might have been limited in small areas near communities foundedon the older beach ridges and natural levees.
(Modified from Sugawara and Minoura, 2013)

3. Countermeasures implemented for disasters
before the 2011 earthquake
Possible coastal disasters that mightoccur around the coastal areas of the
Sendai Bay were summarized in aplan document of coastal management
provided by Miyagi Prefecture (Fig. 3;
Miyagi Prefecture, 2004a). Designs for
hardware-oriented
countermeasures
such as implementation of engineered
coastal dikes were specified in the plan
document to protect coastal areas fromdamage and beach erosion caused bystorm surges and tsunamis. The longterm risk evaluation of the Miyagi-oki
earthquake tsunamis, which wasannounced by the Japan Headquarters
Figure 3: Planning map of shore protection facilities along the southern part of Sendai
Bay (based on Miyagi Prefecture, 2004a).
of Earthquake Research Promotion,
had been considered in the countermeasures. The plan was aimed to protect the coastal lowlands from the hazards of high tides causedby typhoons and storms from low pressure fronts. As a result, coastal dikes with elevations of
5.2–7.2 m have been implemented along the southern Sendai Bay coast, from Gamou in Miyagino ward in Sendai City to Yamamoto Town. Details of the coastal dike design are describedin the plan document of coastal management of Sendai Bay (Miyagi Prefecture, 2004a).
Projected tsunami scenarios in this area were announced in January 2006 by the Investigation Committee of the Earthquakes in Japan and Kuril Trenches, which was organized asa part of the Central Disaster Management Council (CDMC). The scenarios included eight
different earthquake scenarios, such as the multi-segment Miyagi-oki earthquake (M8.2) andthe Meiji-Sanriku type earthquake (M8.6). Possible damage to humans and property, as well as
economic losses, were assessed in each tsunami scenario (CDMC, 2006). In 2004, Miyagi Prefecture announced “the third survey report of projected earthquake scenarios”, which included
prefecture-wide hazard maps that identified the arrival time, maximum water level and inun-

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Field Guidebook

東北大学災害国際研究所

dation area of the projected tsunamis (Miyagi Prefecture, 2004b). Most local communities
have developed their own detailed tsunami hazard maps, which account for the inundation
areas of previous tsunami disasters. The maps were distributed to local residences. However,
the inundation areas and tsunami heights that were caused by the 2011 Tohoku earthquake
were far beyond these projected tsunami scenarios (e.g., Specific Investigation Committee ofCountermeasures for Earthquake and Tsunamis Related to the 2011 Tohoku Earthquake in
CDMC, 2011).
Practical countermeasures for tsunami disasters, including software-oriented measures, hadbeen determined in the plan documents announced by the local governments and tsunami
guidelines published by Miyagi Prefecture (Miyagi Prefecture, 2003). In the software-oriented
countermeasures, a framework for tsunami information and evacuation had been implemented considering the announcement of tsunami warnings from the Japan Meteorological
Agency (JMA) and local Meteorological Offices. Tide gauges to detect tsunamis have been
implemented by JMA and other governmental organizations, including the Ministry of Land,
Infrastructure and Transportation (MLIT) and Geospatial Information Authority (GSI). Somelocal communities in Miyagi Prefecture installed their own acoustic sensors and pressuregauges to detect tsunamis. For example, an acoustic tide gauge had been installed in Yuriage
area in Natori City, just south of Sendai City. Five wave gauges using the Global Navigation
Satellite System (GNSS) are installed offshore of the Tohoku district. The GNSS wave gauges
detected the tsunami waves before the tsunami struck the coasts. The warnings for the 2011
Tohoku earthquake tsunami were upgraded using data from the GNSS wave gauges, although
the timing of the announcement seems to have been too late for evacuation at some locations.

4. Traces of past tsunamis
In the coastal plains of Sendai Bay, little
Table 1. Historical tsunamis that affected the Sendai Bay coast
was known about past large-scale tsunamis
LatitudeLongitude
Tsunami height and location
Year
Month
Day
Magnitude
(°)
(°)
(m)
before the 2011 Tohoku earthquake, which869
71337.5-39.5
143-145
8.6
1611
12
2
39
144.4
8.1
6-8
Iwanumacaused extensive inundation and widespread
1616
9
9
38.1
142
7
1717
5
13
38.5
142.5
7.4-7.5
damage. For example, the 1896 Meiji and the
1793
2
17
38.5
144.5
8.2
2.5-3
Ogatsu
1835
7
20
38.5
142.5
7.0-7.3
5-6
Nobiru1933 Showa Sanriku tsunamis, which have
1861
10
21
38.55
141.15
7.4
2-3
Nobiru
1896
6
15
39.5
144
8.2
0.6
Ishinomaki
been well known as the severest historical tsu1897
2
20
38.1
141.9
7.4
1
Ogatsu
1897
8
5
38.3
143.3
7.7
1.5
Ofunato
1898
4
23
38.6
142
7.2
0.2
Ayukawanamis that struck the coastal areas in Tohoku
1915
11
1
38.3
142.9
7.5
0.6-0.9
Arahama (Watari)
1933
3
3
39.14
144.31
8.1
2.4
Yuriageregion, did not markedly affect the coastal
1933
6
19
38.05
142.3
7.1
0.18
Hachinohe
1936
11
3
36.26
142.065
7.4
0.9
Onagawaareas in Sendai Bay. The height of the 1896
1960
5
22
72.6W
38.2S
9.5
2.4
Yuriage
1978
6
12
38.15
142.167
7.4
0.49
Sendai Port
Meiji Sanriku tsunami was only 0.6 m on the
coast of Ishinomaki City in the north of Sendai
Bay. Some damage by the 1933 Showa Sanriku tsunami was documented from Yamamoto
Town in the southernmost part of Sendai Bay. However, very little or no damage was reported
from other locations in the bay. The 1960 Chilean earthquake tsunami gave significant effects
to the Pacific coast of Japan. The Sanriku Coast was again severely damaged by the tsunami.
Nevertheless, the tsunami heights ranged 2–3 m in Sendai Bay, and did not cause notabledamage (Watanabe, 1998). The 1978 Miyagi-oki earthquake caused severe damage to humans
and urban infrastructure because of severe seismic vibration, but the observed tsunami heightat Sendai New Port was around 0.5 m; the effects of the tsunami were quite minor (Watanabe,

7The 2011 Great East Japan
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Field Guidebook

1998). The Miyagi-oki earthquake has been
regarded as a characteristic earthquakewith a 37-year recurrence interval. Up tofive preceding Miyagi-oki earthquakes
during 1793–1936 have been identified
from historical documents. The oldest, the1793 Miyagi-oki event, is regarded as amultiple-segment earthquake. It generated
a 2–5-m-high tsunami along the Iwate andMiyagi coasts. Nevertheless, no considerable damage was reported from the coastal
areas of Sendai Bay.
Widespread and severe damage causedby the 1611 Keicho earthquake tsunami wasreported from the Sanriku coast and Sendai
Bay (Watanabe, 1998). Historical records
are few. Most reliable records are obtainablefrom the Sanriku area. The tsunami heights
and damage in Sendai Bay have not yet been
Figure 4: AD869 Jogan tsunami deposit derived from the Sendai Plain (modified
clarified. According to local traditions, masafter Sugawara et al., 2012).
terless samurais (ronin people) had settled in
Sendai Plain, including the Arahama area,
to cultivate lands devastated by the 1611 tsunami. An anecdote was reported from Iwanuma
City: a small fishing boat was washed upstream along the Abukuma River, where it drifted
onto a branch of a pine tree (legend of Sengan-matsu). Recent historical and geological studies
indicate the possibility that the magnitude of the 1611 earthquake and the size of the ensuing
tsunami was equivalent to the 2011 event. However, surficial sediments of the coastal plains
have been under the influence of land development since the 1611 tsunami. Geological researchmight work in coastal lakes and ponds, where surficial sediments are likely to be preserved
under natural conditions. A sand layer corresponding to the 1611 Keicho event, together witha sand layer by the 869 Jogan tsunami, was identified from a coastal pond (Suijin-numa) in
Yamamoto Town (Sawai et al., 2008).
The only historical account of the 869 Jogan earthquake tsunami is found in Sandai-jitsuroku, which was written and compiled as a national history of ancient Japan. The collapse ofbuildings and ground fissures caused by the seismic shocks were described in the document,along with extensive inundation of the coastal plain. The Jogan tsunami deposit was firstreported from the Sendai Plain by Minoura and Nakaya (1991). Results of subsequent studies
have implied that the tsunami reached 3–4 km from the past coastline. Minoura and Nakaya(1991) also found other two sand layers, which might have been deposited by the predecessors of the Jogan event. The earlier one was dated at 50±100 AD; another one was dated at740±100 BC. Subsequent studies also found sand layers corresponding to the Jogan event’s
predecessors (Sawai et al., 2007, 2008, 2012). A sand layer by the predecessor of the Jogan
tsunami at ca. 2,000 yrBP was found from the ancient rice paddies in archeological sites in
Sendai Plain. Recent archeological studies have analyzed the distribution of the archeologicalsites and artifacts, revealing that coastal villages were abandoned for a long time after the8The 2011 Great East Japan
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東北大学災害国際研究所

large-scale tsunami, and that inland areas free from the tsunami disasters were developed as
new settlements (Saino, 2012).
According to the geological studies, the 2011 Tohoku earthquake tsunami is apparently
a recurrence of the Jogan tsunami, which leads the 2011 Great East Japan Earthquake as aso-called “disaster with 1,000-year periodicity.” However, we cannot distinguish tsunami
layers deposited within few to a few tens of years because of the limitations of samplingand dating of sediments. In case an aftershock or induced earthquake of the Jogan event had
created a large-scale tsunami and deposited sandy sediments, it is difficult to discriminate itfrom the original Jogan sand layer. It is not necessary to add that the next large-scale tsunami
is expected to take place some time during the next 1,000 years.
(Modified from Sugawara and Minoura, 2013)

5. Damage by the Great East Japan Disaster in Sendai Plain
The seismic intensities (in Japanese scale) of the2011 off the Pacific Coast of Tohoku Earthquakeat each city were 6+ at Sendai City, Natori City,
and Yamamoto Town and 6- at Iwanuma City and
Watari Town. A major aftershock occurred on April
7, 2011 with intensity of 6+ at Sendai City and 6- at
Natori and Iwanuma Cities. Damage to buildings andinfrastructure because of the aftershock was severe.
During the main and after shocks, liquefaction incoastal areas, landslides in hilly areas, and collapseof developed land were not unusual.
The tsunami arrival time at the Sendai Plain was
60–70 min after the earthquake. According to an
eyewitness account by a helicopter crew of the Ministry of Land, Infrastructure, Transport and Tourism(MLIT), tsunami inundation started from the northnear the Sendai New Port. The initiation of the tsunami inundation in the area between the Abukuma
and Natori Rivers might have been the latest in the
Pacific coast of Tohoku. The tsunami height on the
Sendai Plain was ca. 8 to 9 m along the shoreline. At
Figure 5: Elevation (left) and maximum flow depth (right: tsunami heightsome places, tsunami heights were recorded as morefrom the ground) based on Goto et al. (in press).
than 10 m (Fig. 5, Mori et al., 2012). Tsunami heights
on the Ishinomaki Plain, located north of Sendai Bay,
were generally lower than those at the Sendai Plain. According to numerical modeling (Fig.
6), the tsunami near Sendai Airport reached ca. 4 km inland from the coastline within 22
min after its arrival time (Sugawara and Goto, 2012). Tsunami inundation in the Sendai and
Ishinomaki plains ultimately reached 4–5 km inland from the coastline (Fig. 7).
Seawater flooding continued for approximately 2 months after the tsunami in some places.
Damage to drainage systems and region-wide coseismic subsidence were also reasons why seawater flooding had persisted for a long time. Areas with zero-meter elevation were expanded

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Field Guidebook

Figure 6: Numerical results of tsunami inundation of the Sendai Plain (near the Sendai Airport): 15:56JST (left) and 16:07JST (right).

because of the coseismic subsidence. Before theevent, about 3 km2 areas from Sendai City to
Yamamoto Town had sub-zero elevation. However, that area with sub-zero elevation expanded
to 16 km2 after the event. Natural drainage of thetsunami seawater was not expected at that time.
Consequently, the flooded water was drained
from many places using mechanical pumps.
It took more than a few weeks to complete theseawater drainage.
Death tolls in the Sendai Plain (Tagajo,
Sendai, Natori, Iwanuma Cities, and Watari andYamamoto Towns) eventually mounted to 3,244
people. In addition, 98 people remain missing.
Regarding damage to humans and property,
39,923 and 118,309 buildings were completely or
partially destroyed, respectively (Miyagi Prefecture, 2014).
(Modified from Sugawara and Minoura, 2013)
Figure 7: Comparison of the inundation area by the 2011 tsunami (red) andpre-tsunami hazard map (blue). Central Disaster Management Council(2011).

6. Tsunami countermeasures implemented after the 2011 event
The 2011 Tohoku earthquake and tsunami caused severe damage to humans. Infrastructure
was also severely damaged, including the airport, sewer treatment facilities, and agricultural
fields. The 2011 Tohoku disaster underscores the fact that engineered coastal facilities such as
control forests and coastal dikes are not always effective to protect people and property froma large-scale tsunami. After the 2011 disaster, both national and local governments came toadvise multiple layers of protection, including elevation of roadways and railways, and building
canals parallel to the shoreline to reduce the tsunami energy and consequent damage (Fig. 8).
For the restoration of the tsunami-devastated coastal dikes, an important issue is to determine
the design height of dikes intended as countermeasures against future tsunamis. The height ofan extreme, but infrequent, tsunami, such as the 2011 event (so-called level-2 tsunamis), was
not adopted for design. Instead, the height of more frequent, but less intensive tsunamis, which

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東北大学災害国際研究所

have a recurrence interval of a
few tens of years to hundredsof years of (so-called level 1
tsunamis), was used as thebasis of designing the coastal
dikes. The design height of thereconstructed coastal dikes
Figure 8: Image showing multiple defenses for tsunami countermeasures (Miyagi Prefecture, 2011a).
accounts for storm surges(Fig. 9). In the southern Sendai
Bay, the design height of thedikes was determined to beas high as 7.2 m above Tokyo
Peil (T.P.) (Miyagi Prefecture,
2011a, b).
Except for some locationsin the southern Sendai Bay,coastal dike reconstruction
Figure 9: Images showing how to infer the height of a sea structure against a Level 1 tsunami andthe estimated tsunami wave height at the southern part of Sendai Bay (Miyagi Prefecture, 2011b).
has been conducted by thecentral government. The
reconstruction was started near important infrastructure, such as the Sendai Airport andsewerage disposals. By December 2013, approximately 60% (18 km) of the coastal dikes had
already been reconstructed. Considering the analysis of processes and patterns of the damage
caused by the 2011 tsunami, the new coastal dikes were designed to be more resistant against
the tsunami overwash and scouring (Committee of the Tsunami Countermeasures along theCoast, MLIT, 2011). The tsunami deposits were used to construct the embankments for thecoastal dikes. In some areas, the lee side of the coastal dikes was covered by soil. Then trees
were planted there to produce a “green coastal dike”, to maintain harmony with the naturalenvironment and scenery.
In tsunami-devastated areas, most local governments designated restrictions for residency
near the coastal zones. Public housing for the victims will be constructed on high ground andinland, to facilitate the movement of people from vulnerable areas.
As for software-oriented countermeasures, communication systems such as wireless networks were reconstructed to send tsunami information or evacuation advisories swiftly to the
public. Redundancy is important for disaster communication. Local governments chose toincorporate communication tools of various kinds, such as FM broadcasts, mobile phones, aswell as Twitter and Facebook.
Because most areas of the Sendai Plain are lower than 3 m, it was also regarded as importantto set up high evacuation areas. Local governments are planning the construction of tsunami-evacuation towers in coastal areas. Evacuation stairs with banisters were attached on theembankment of the Sendai Tobu Road. Although the road was not designed initially for tsunami
evacuation, many people climbed up the embankment and survived the tsunami in 2011. Since
implementation of the stairs, safety exercises have been conducted periodically.

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Field Guidebook

7. Stops
Stop 1

Near the Nakahama Elementary School in Yamamoto town

You might find the remnants of Nakahama Elementary School building and “Tsunami Bay”
at this stop (Fig. 10). The tsunami rushed into the two-story elementary school building, which
was made of reinforced concrete, through the windows in the east side. The waters reached up
to the roof of the second floor. Nevertheless, not one of the 90 people in the building, includingchildren, teachers and some local people, died. They all succeeded in evacuating to the roof
terrace. The tsunami did not ultimately flood the terrace. Tsunami-damaged buildings havebeen disappearing as clearing and reconstruction work progresses. Few remain in southern
Miyagi Prefecture. People have begun to devote attention to such buildings as tsunami memorials. Local governments are now considering the use of the damaged buildings as monuments.
"Tsunami Bay" is located 200–300 m east of the elementary school building. It is visible
from the building terrace, from which one can reach the bay with a five-minute walk. The
2011 tsunami induced substantial sediment transport and created many erosional features allaround the sandy beaches of southern Sendai Bay. Mechanisms and factors involved in thecreation of tsunami bay are the retreat of the sandy beach because of long-term coastal erosion,
the collapse of engineered dikes caused by the tsunami overwash and scouring, and formationof deep ditches in the lee side of the dike. The Tsunami Bay is a rare landscape showinginteraction between the tsunami and anthropogenic coastal protection.

Figure 10: Overview of old Nakahama Elementary School of Yamamoto town (building with orange roof in left centerside) and “Tsunami Bay (eroded arc-shaped coast in right center side).”12

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東北大学災害国際研究所

Stop 2Hill of millennium hope"Hill of millennium hope" is a reconstruction project planned for Iwanuma City. The coastal
area of Iwanuma City was damaged by the tsunami, as were Sendai and Natori Cities. The
tsunami debris will be used for construction of the hill (Fig. 11). The planned height of the hills
is 8 m. The hill is designed to mitigate the effects of infrequent large-scale tsunamis such as
the 2011 event, and to be tsunami-evacuation areas. The construction of a part of the hill wascompleted in June 2013. Work is expected to continue in the future.

Figure 11: Schematic of "Hope Hill for a thousand year perspective" as a reconstruction plan in Iwanuma city.
http://www.city.iwanuma.miyagi.jp/kakuka/040700/documents/image_illustration.pdf

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Stop 3Around Sendai Airport

Sendai Airport is located across Natori and
Iwanuma Cities. The airport area was originallyused for agriculture. During World War II, theJapanese army set up an air base in 1940 for pilot
training. After the war, the US army occupied
the base. After occupation by the US army hadceased, the land was again used for agriculture
for several years. The present Sendai airport was Figure 12: Damage conditions of sand embankments and preserved forests: (A)photograph taken on November 11, 2010 by Dr. Kentaro Imai, Tohoku University),and (B) photograph taken on May 5, 2011 (Sugawara and Minoura, 2013).
opened for domestic flights in 1957. International
flights to the airport began in 1990.
Elevation of this low-flat area used to bearound 0–1 m. The land became much lower
than sea level because of coseismic subsidence
resulting from the 2011 earthquake. No damage
occurred to commercial airplanes from the tsunami, but many small airplanes and helicopters
Figure 13: Cross section of topography and tsunami inundation height near thewere completely washed away. The tsunami flow
Sendai airport (Goto et al., 2011).
height measured at the airport terminal building
was 5.6 m above mean sea level (Mori et al. 2012). Although the tsunami completely inundated
the first floor, 1,422 people including travelers, staff members, and local residents had evacuated to and survived on the second and the third floors of the building. Recovery of the airport
was done by the Japanese Self-Defense Forces and aid from the US Air Force and Marines
under a campaign designated as “Project Tomodachi.” The airport was soon recovered andused for emergency helicopter operations four days after the tsunami. The runway was cleared
five days later. Commercial flight operations were resumed one month thereafter.
Along the Sanriku Coast, in particular in the northern part of Kamaishi City, seawalls with 10
m high were implemented in consideration of the 1896 Meiji and 1933 Showa tsunamis. However,the coastal dikes in Sendai Bay and along the Joban Coast, which have a typical height of 5–6
m, were designed to protect the coast from storm surges because the effects from the 1896 and1933 tsunamis were minor in Sendai Bay, and because pre-2011 coastal protection was intended
mainly as a countermeasure against high tides and storm surges. The coastline from Kitagama,east of the airport, to Yuriage, south of Natori River, was not protected by engineered dikes. Sand
embankments covered by plants and trees were built in this area (Fig. 12A).
The 2011 tsunami height was 10.6 m T.P. (inundation depth = 9.6 m) behind the sand dunes
and around 3–4 m (inundation depth = 2–3 m) at distances of 0.5–2.5 km from the coast (Gotoet al., 2011; Fig. 13A). The tsunami reached 2.7 m elevation near the Sendai Tobu Road at
about 4.8 km from the coastline. The flow depth there was about 0.2 m. The tsunami flooding
near the Sendai airport can be seen in a video taken by the Japan Coast Guard. The video is
crucially important for estimating the speed of the tsunami flow on land. Based on analysis of
the video, the wave front velocity was estimated at about 4 m/s at distances of 1.1–2.1 km fromthe coast (Goto et al., 2011). The high flow speed was one cause of the large-scale erosion of
the sand dunes (Fig. 12B).
(Modified from Sugawara and Minoura, 2013)

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東北大学災害国際研究所

Stop 4

Yuriage area

Figure 14: (A) Hiyoriyama Hill in the Yuriage area. (B) Damage to the Yuriage area in a photograph taken from the top of Hiyoriyama Hill (June24, 2011).

Yuriage area in Natori City is a fishing village located near the mouth of the Natori River.
Even at the time of the transgression during the Jomon period, the coastline of this area isthought not to have been much different from that of the present coastline because of substantial sediment supplied from the river (Matsumoto, 1981). Elevated areas are found on
natural levees near the river (Matsumoto, 1981). The levees have been used for residential
areas for a long time. Inhabitation and formation of communities started during ancient times
and continued to the middle ages in Japan (Heian period). Markedly rapid development of the
Yuriage community took place during and after the Edo period (Kahoku Shimpo News, 2012).
After excavation of the Kobiki-bori Canal, which is a part of Teizan Canal and which connects
the mouths of the Abukuma and Natori Rivers, Yuriage was a lodgment of products such as
timber and rice. The village was changed to a fishing port after the commercial development of
Shiogama and Ishinomaki cities in the northern part of Sendai Bay.
Hiyoriyama is a small hill located about 800 m from the sea. The top of the hill offers apanoramic view of the area (Fig. 14). The 6.3-m-high hill was built using sediments dredged
from the Teizan Canal. Wooden houses in
the residential area within 1 km from thecoastline were washed away completely by
the tsunami. The Hiyoriyama hill is the only
high ground in this area, but the tsunami
overtopped the hill and washed out somestone monuments including a memorialof the 1933 Showa-Sanriku tsunami. The
tsunami height measured on this hill was
7.9 m (Mori et al., 2012). The 911 casualties
in Natori City include 40 missing, most ofwhom were reported from Yuriage (750
deaths out of 5,612 pre-disaster populationin this area). At present, many people,
Figure 15: Stopped clock at Yuriage Elementary School.
including relatives of victims, volunteers

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Field Guidebook

and tourists, frequently come to the hill andoffer prayers for the tsunami victims.
Yuriage Junior High School andYuriage Elementary School are located,
respectively, at 1.8 km and 2.1 km from thecoastline. The measured tsunami height
was about 4.4 m at these locations (Moriet al., 2012). Hundreds of people had evacuated to the buildings and survived thetsunami. A high water mark is still visibleat the Yuriage Elementary School building
together with a clock, which was stopped
by the 2011 event (Fig. 15). A pedestrian
bridge can be found at the crossing point of
Figure 16: Pedestrian bridge at the cross junction of the prefectural road no. 10 andthe city road.
the Prefectural Road 10 and the City Road
(Fig. 16). At the time the tsunami struck,some people climbed the stairs andsurvived on the top of the bridge.
A sign on the bridge’s pillar shows
the tsunami height. In October 2011,
Natori City’s government proposeda reconstruction plan for the Yuriage
area, which includes leveling the
ground to 3 m higher than it is currently and calling the local people toreturn to the area. The government
produced a mock-up of the elevatedland, together with a planned layoutof new coastal dikes, to let people
know how high the area will be
and how safe the residents will be
Figure 17: Land elevation change before and after the 2011 earthquake at the GSI standard
against large-scale tsunamis in the
point in Natori (Sugawara and Minoura, 2013).
future. However, many people wantto move away from Yuriage, or have already left and made new homes in other areas. Because
three years have passed since 2011, the expected population of the new Yuriage community has
been decreasing. The reconstruction plan has been revised many times.
An automatic observation station of geodetics, operated by the Geospatial Information
Authority of Japan, is installed in the Yuriage Junior High School grounds. At the time of the2011 earthquake, a coseismic subsidence of 28 cm took place at this point (Ozawa et al., 2011).
Since then, the elevation has recovered because of the postseismic crustal deformation. Halfof the coseismic subsidence was cancelled out by the beginning of December, 2012 (Fig. 17).
According to detailed analysis of the geodetic data, the postseismic uplift is occurring in areasfrom the Oshika Peninsula to the Sendai Plain, whereas postseismic subsidence is occurring in
the northern and middle Sanriku Coast (Iinuma et al., 2012).
(Modified from Sugawara and Minoura, 2013)16

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東北大学災害国際研究所

Stop 5Idoura Lagoon

Idoura Lagoon is located north of the mouthof Natori River. A notable change in topography
occurred in this lagoon because of the 2011 tsunami.
The sand bar that borders the lagoon was eroded
severely and flattened by the tsunami. Most of thebar became submerged.
The lagoon was selected as an important wetlandarea of Japan, considering the preservation of biodiversity in many environments, including wetlands,
rivers, lakes and lagoons. Another lagoon, Hiroura,
is located further to the south. The mouth of Natori
River changed its position because of major riverflooding. It had been wandering for a long timearound the two lagoons. For example, an old topo- Figure 18: Topographic map at the Natori River mouth (1:50,000) (basedon Sugawara and Minoura, 2013).
graphic map shows that the river flowed out fromthe Hiroura Lagoon (Fig. 18). Guide walls were built
recently to stabilize the river mouth. The average water depth of the lagoon is 0.5–1.0 m.
The maximum water depth is 2.0 m. Waterway traffic is not convenient even for small boats
because of the shallow bathymetry.
Figure 19 presents a view of
the remaining part of the sand bar.
The black sand includes plenty ofiron minerals (magnetite grains).
Sediments supplied from the riverare placed under the influence ofsegregation by coastal currents.
Because of the difference indensity, heavier grains tend to
Figure 19: (A) Deposition of iron sand at Idoura; (B) view from the southern end of the sand bar
remnant (based on Sugawara and Minoura, 2013).
remain near the sediment source.
Lighter grains are washed awayfrom the source by the northward
alongshore currents in Sendai
Bay. Using iron-rich sand, ironmanufacturing was conductedaround 70 years ago for military
purposes (Editorial Board of
Rokugou wo saguru kai, 2005)
Figure 20 shows LIDAR
topography near the Idoura
Lagoon, as surveyed respectively
in the winter of 2005, March
2011, and May 2011. In March
Figure 20: Digital Elevation Model (5 m grid) before and after the tsunami, based on Geospatial
2011, the lagoon was connected
Information Authority of Japan (based on Sugawara and Minoura, 2013).

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Figure 21: Google Earth images before and after the 2011 earthquake and tsunami at the Natori River mouth.

to the open ocean because of the sand bar erosion. In May 2011, sediment accumulation had
already begun, and a new sand bar had begun to be formed west of its earlier position (See
GoogleEarth satellite imageries). Results show that the lagoon area was reduced considerably.
Similar extensive erosion of the sand bar was observed in Gamou Lagoon, located north of the
Arahama area. However, the post-tsunami recovery process of coastal geomorphology in the
Gamou Lagoon differs somewhat from that of the Idoura Lagoon. Satellite images show thatthe sand bar of the Gamou Lagoon almost entirely recovered its original shape soon after thetsunami.
The tsunami height was measured at 9.3 m near the Natori River embankment, which islocated south of the residential area (Mori et al., 2012). The community near the Idoura Lagoon(called Fujitsuka) had around 90 houses. The 2011 tsunami washed away most of the houses
and caused 24 fatalities (Kahoku Shimpo, November 28, 2012). Live video taken by an NHK
helicopter clearly captured tsunami flooding in this area. According to analysis of the video,
the tsunami front speed and the flow speed were estimated respectively at 6 m/s and 8 m/s(Hayashi and Koshimura, 2012). The intense seismic shocks created a yawning gap acrossthe beams of the Yuriage Bridge near the river mouth. Road traffic was stopped completely.
Although the tsunami nearly washed over the bridge, a policeman left behind on the bridge
survived.
(Modified from Sugawara and Minoura, 2013)18

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Field Guidebook

東北大学災害国際研究所

Step 6 Arahama area
Arahama means “a wildbeach” in Japanese. Twoareas along the Sendai Bay
coast are called Arahama:
one in Wakabayashi ward,
Sendai City, and another one
near the Abukuma River
in Watari Town. Arahama
in Sendai City has anotherFigure 22: (A) Arahama area before the 2011 tsunami; (B) Tsunami hazard map located near thename, Fukanuma, whichcoastal forest (photograph taken on May 6, 2009) (Extracted from Sugawara and Minoura, 2013).
means “deep pond.” In fact,
most of Sendai Plain, including the Arahama area, is marshland, as noted in Section 2. Swimming has been prohibited in general at most the beaches on the Sendai Bay coast because ofrough waves from the open ocean. Arahama is an exceptional swimming beach because of theimplementation of detached breakwaters.
Some historical records reveal that the Arahama area was developed after the 1611 Keicho
Sanriku earthquake tsunami. At that time, people from other places settled in the tsunami-devastated area and cultivated the land. The Arahama area consisted of an old community in thenorth and a new town in the south. The northern area was a fishing village. It has maintained its
historic housing (Fig. 22A). The southern area was developed during and after rapid economic
growth in the 1960s. There were about 750 houses in the Arahama area before the 2011 tsunami(Kahoku Shimpo, 2012). As in other areas, almost all the wooden houses were washed away;
186 people lost their lives. Arahama area, a famous location of the 2011 tsunami disaster, hasbeen covered frequently in mass-media news reports. A tsunami memorial and a statue of the
Buddhist Goddess of Mercy were donated and placed next to the seawall.
The tsunami height near the coastline was about 9–12 m (Mori et al., 2012). Figure 22B shows
the tsunami hazard map published before the 2011 tsunami. As described earlier, the projectedearthquake scenario in this area before the 2011 tsunami was the Miyagi-oki earthquake, which
had 37.1 years of recurrence and typical magnitude of 7.3–7.5. The largest known Miyagi-oki
earthquake occurred in 1793 (5th year of the Ansei period) with magnitude of 8.2. Considering
the fault rupture in multiple segments, tsunami heights of 2–5 m were predicted along the Iwate
and Miyagi coasts. Considering the migration of tsunami effects by the seawalls and coastal
forests, the tsunami inundation area had been assumed to terminate within the coastal forestor the Teizan Canal, or at most around the building of Arahama Elementary School (Fig. 7).
Although the 2011 tsunami arrived at Sendai and Natori coasts about 70 min after thetime of origin, no natural high ground can be found throughout the Sendai Plain. The highembankment of the Sendai Tobu Road was a possible evacuation place, but it was 3 km distantfrom the coast. Therefore, it is expected to be difficult for people to evacuate from the tsunami
inundation area by walking if they had decided to escape immediately before the tsunami
arrival. Many people used their own vehicles for the tsunami evacuation, causing severe traffic
jams. This was confirmed by NHK air live broadcasts and much other video footage. Many
private cars had concentrated on the roads and were forced to stop because of the traffic jams.
The tsunami flooding inundated the entire area.

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The Arahama Elementary School building was
the only possible tsunami evacuation shelter. It
was sufficiently high and robust against tsunami
inundation. The tsunami reached the second floorof the building (tsunami height = 7.8 m). Nevertheless, 233 local residents, with 87 students andteachers, evacuated to upstairs areas and survived
on the rooftop (Kahoku Shimpo, 2012). Those
who were in bad physical condition were rescued
earlier by helicopters. Others were rescued byboat. At present, the school building is no longer
used for its original purpose, but it is expected to
be used again as an emergency evacuation shelter
for future tsunamis and evacuation drills.
Because of large-scale erosion by the tsunami, Figure 23: 1:50,000 land elevation map of Arahama (in 1912) (Extracted
from Sugawara and Minoura, 2013).
many topographic undulations were formed on
the beach ridges, which include residential areas.
The erosion was as deep as 3 m at the back side of
the coastal dike. Seaward of the dike, the tsunami
erosion formed many waterways that cut acrossthe sandy beach. Tanaka et al. (2011) pointed outthat old river channels played an important role
for the creation of these waterways during thetsunami backwash. A topographic map publishedduring the Meiji period shows a small water bodynorth of the Arahama area. It was connected toponds located northwest of the area: Kitanaganuma and Onuma (Fig. 23). In an older map, thewater body was shown as a river. Consequently, Figure 24: Management office of the coastal adventure park.
the location of the breaching of the sandy beachcorresponds to the old channels (Tanaka et al., 2011).
Formation of the waterways on the sandy beach can be confirmed by Google Earth images
taken on March 18, 2011. However, the waterways were filled up by sand, as shown in theimage taken six days later on March 24, 2011. Parts of the coastal dikes on the beach ridge werecompletely collapsed. Some of the fragments, which consisted of large concrete masses, weremoved inland as far as 100 m. Nevertheless, the detached breakwaters, which comprise pilesof blocks, were not moved at all.
Figure 24 shows the coastal adventure park located 400 m from the coast. This place wasonce a pond, as presented in Fig. 23. The pond became filled by soil and an artificial hill had
been constructed. Then the park was opened on it. The hill elevation was greater than 15 m,
and the 2011 tsunami did not reach on the top. The tsunami near the coast, about 10 m high,inundated the first floor of the office located in the west side of the hill. Reportedly, five people
survived on the hill.

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東北大学災害国際研究所

Stop 7

Teizan canal

A remarkable feature in the
coastal zones of Sendai Bay is asystem of shore-parallel waterways,
consisting of Teizan, Tona, andKitakami canals (Fig. 2). These
canals are situated approximately
500 m from the coastline. The
Teizan canal connects the mouth
Figure 25: (A) Landscape of Teizan canal before the Tohoku Great Earthquake and Tsunami onof Abukuma River and Shiogama
January 29, 2010. (B) The disaster landscape of Teizan canal after the Tohoku Great Earthquake
Port in Matsushima Bay with lengthand Tsunami post-disaster, shot with same position and direction on March 17, 2011. (Reprinted
from Sugawara and Minoura, 2013).
of about 27 km. It consists of three
portions, named the Kobiki-bori,Shin-bori, and Ofunairi-bori canals. The Tona canal, about 4 km long, extends from Matsushima
Bay to the mouth of Naruse River via Nobiru area in Higasimatsushima City. The Kitakami canalextends from the left bank of Naruse River to Old Kitakami River in the center of Ishinomaki
City, via the Jo River in Ishinomaki Industrial Port with length of about 14 km. The canal system,with total length of 44 km around Sendai Bay, is the largest in Japan.
The Kobiki-bori canal is the oldest among the Teizan canal system. It was excavated by
Sir Kawamura Magobe Shigekichi (1575–1648) in the early Edo Period. Although the ageof the construction has not yet been determined, it is likely that the canal was constructed
before 1633 (the tenth year of Kan'ei Period), based on a drawing made during that period(Goto, 2010). Some historical documents suggest that the construction was conducted during
1597–1601 (Civil Engineering Section, Miyagi Prefecture, 2008). However, considering thehistorical background (the civil war lasting from the middle age of Japan until the Edo Period),
it might have been difficult to carry out a project to excavate the big canal during this period.
Because the castle town of Sendai had developed, the Ofunairi canal was excavated during
1661–1658, to enhance transportation. The construction of Shin-bori canal was conductedduring 1870–1872 (3rd – 5th year of Meiji Period), to provide jobs to Samurai people who losttheir salaries because of the Meiji Restoration. "Teizan" was named in the Meiji Period after
the honorific name of the feudal lord of Sendai: Masamune Date. The Teizan canal is locatedin the marshlands in the beach ridge III. Based on the understanding of the nature of Sendai
Plain, it is likely that ancient people might have used the area. The Teizan canal was once very
shallow and largely carved. The canal was repaired and expanded extensively during and after
the Meiji Period. The canals were linearized and dredged. Now they have a typical width ofabout 50 m and depth of about 3 m. Since the Meiji Period, the importance of the canals for thetransportation of products has been reduced because of the development of terrestrial traffic.
The main use of the canal is for leisure, such as fishing and boating.
Because of the impact of the 2011 tsunami, the canal embankments collapsed. Most of thecanal gates and bridges were washed away (Fig. 25). Nevertheless, a post-tsunami survey
revealed that the tsunami height was reduced by about 3 m across the Tona canal in Higashimatsushima City, suggesting that the canal can reduce the impact of the tsunami waves (Goto,2012).
(Modified from Sugawara and Minoura, 2013)

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Stop 8Sendai Tobu Highway

Figure 26: Landscape of contrasting disaster situation in Sendai eastern highway on March 12, 2011. (Reprinted from Sugawara and Minoura,2013): (A) west side of the highway (land side); (B) east side of highway (sea side).

Sendai Tobu Highway runs parallel with the coastline at a distance of about 2–3 km from
Sendai city to Watari town (Fig. 2). Since opening in 1994, this highway had been connectedwith the Joban highway in the southern part and with the Sanriku highway in the northern
part. This highway has a high embankment formed at the height of 7–10 m above sea level.
In the Sendai Plain there are few areas with higher ground where one might evacuate froma tsunami. Therefore, the government and residents had held conferences with the highway
company during a few years before the 2011 earthquake, negotiating for the use of highwaysfor evacuations. At the time of the 2011 earthquake and tsunami, they had not yet reached anagreement and preparation for usage of the highway. Nevertheless, about 350 people evacuatedby climbing to the highway embankment (Kahoku Shimpo, December 22, 2012). Now evacuation stairs have been provided in five places along the highway. Drills to use them have been
held.
The tsunami entered the inland side through the underpass and the part of the elevated way.
The tsunami force was reduced considerably across the road, and the appearance of the damage
differed greatly east and west of the highway (Fig. 26). Particularly, the effect of preventing thedebris inflow was very large. The plan of relocation and raising of the road was adopted near
the coast road (Shiogama-Watari line of country road No. 10) because of the good example ofits unexpected effect as a breakwater (Fig. 8; Disaster Recovery Office, Sendai city, 2011).
(Modified from Sugawara and Minoura, 2013)

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東北大学災害国際研究所

Stop 9Around Sue-no-Matsuyama

Figure 27: March 31, 2011: (A) landscape of Sue-no-Matsuyama; (B) landscape of damaged area immediately after the Great Tsunami nearSue-no-Matsuyama (tsunami depth about 2 m).

Sue-no-Matsuyama (Fig. 27A) with big pine trees is located on a small hill behind the
Houkokuji temple beside Sunaoshi River south of Tagajo Station. This area became famous
because of the legend of the Jogan tsunami in Kokin-Waka-shu, the Japanese ancient anthology
of poems, (e.g. Shimizu et al., 2000). That poem is the following.
Kimi wo Okite Adashi Kooro wo Waga Motaba Sue-no-Matsuyama Nami mo Koenamu(Anonymous, Kokin Waka –shu)
It means that “If I forgot you to love another, waves have broken over Sue-no-Matsuyama(The end of a hill with pine trees, by a literal translation). I will never forget you as the waves
have never broken over Sue-no-Matsuyama.”
First, Yoshida Togo, the famous historical geographer, had interpreted this poem in an
academic view. He interpreted that the phrase of Sue-no-Matsuyama has been used as “Utamakura”, a symbolic decorative expression, and indicated that no wave had broken over thisplace (Watanabe, 2012). However, there is another interpretation that the tsunami had broken
over the Sue-no-Matsuyama.
The maximum altitude of Sue-no-Matsuyama on a hill is about 13 m. Eastern and southernparts of Sue-no-Matsuyama are parts of the old beach ridge I. The lagoon extended along theinner side of this beach ridge during the Jomon to early Heian periods (Board of Education in
Sendai City, 2010). Some remnants, including Numamukai, are still present around this coastallagoon. Sandy deposits formed by the Jogan tsunami have been found in these remains. During
a few hundred years after the tsunami at the Yayoi period, as described above, the base of
production moved inland in the Sendai coastal plain. However, such a change was not observed
after the Jogan tsunami. Consequently, it has been interpreted that effects of the Jogan tsunami
were smaller than those of the Yayoi tsunami. It is likely that tsunami sizes are related to thesedifferences but there are expected to be cultural backgrounds of each age. The development

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Field Guidebookof agricultural production became important for the usage of coastal areas as the preferred
location for agricultural work (Saino, 2012). It is likely that villages in the Sendai plain were
restored rapidly by the victims of Jogan earthquake and tsunami. Actually, tsunami deposits
formed by the Jogan tsunami were scattered throughout a wide area on the Sendai plain and are
not continuous. This is true probably because not only was the distribution of tsunami deposits
affected by the local topography, but also the deposits were removed by human activities after
the Jogan tsunami.
Although geography (e.g., topography and shoreline position) at the time of the Jogan
tsunami differed from the present one and although direct comparison of the tsunami size
is difficult, the 2011 tsunami did not break over the Sue-no-Matsuyama. The flow depth at
Sue-no-Matsuyama was 2–3 m during the 2011 tsunami. In Sendai Plain, many houses were
washed away when the flow depth became greater than 2 m. However, around the Sue-noMatsuyama, fewer houses were washed away even though the flow depth became greater than
2 m, probably because the flow velocity was slow, despite the flow depth. However, humanand material damage was extensive because of the impact of automobiles because this area
is located near the Sendai Port, where many cars had been parked for export by freight ferry.
(Modified from Sugawara and Minoura, 2013)24

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東北大学災害国際研究所

References
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Central Disaster Management Council, Expert Committee for Subduction Earthquakes around the Japan and Kuril Trenches, 2006.
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Central Disaster Management Council, Specific Investigation Committee of Countermeasures for Earthquake and Tsunamis Related
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Disaster Recovery Office, Sendai city, 2011. Summary of Reconstruction Plan of Sendai City, 11p. (in Japanese)
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Community Center, 19p. (in Japanese)
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Goto, M., 2010. The best canals in Japan: Teizan Canal, Kitakami Canal, and Tomei Canal (Edition of recent times) with the story ofwater and sand. Newsletter of Aoba-Kogyo-kai, 54, 31-38. (in Japanese)
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Iinuma, T., Hino, R., Kido, M., Inazu, D., Osada, Y., Sato, M., Ohta, Y., Fujimoto, H., Ito, Y. and Suzuki, S., 2012, Postseismic slip
distribution associated with the 2011 Tohoku Earthquake (M9.0) based on terrestrial and seafloor geodetic data. Am. Geophys.
Union 2012 Fall Meet., Abstr. San Francisco, T13F-2694.
Ito, A., 2006. Variation of the coastline during the historical age along the Sendai Plain. Bulletin of the Department of Education,
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Matsumoto, H., 1981. Alluvium on the Sendai Plain and the changes of coastline during the postglacial period. Geographical Review
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Matsumoto, H., 1994. Beach erosion and coastal structures along the Sendai Bay. Geographic research for the environmental modification due to the regional development. Report of Research Project of Tohoku Univ. 45-53. (in Japanese)
Minoura, K. and Nakaya, S., 1991, Traces of tsunami preserved in inter-tidal lacustrine and marsh deposits: Some examples from
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Miyagi Prefecture, 2003, Guideline for the tsunami countermeasure in Miyagi Prefecture. (in Japanese)
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Miyagi Prefecture, 2004a. Master plan for the coastal protection along the Sendai Bay (Planning), 66p. (in Japanese)
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Earthquake

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Note: Japanese titles were translated by authors.

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